The present invention relates to a two piece pin and sleeve stripping system. In particular, this invention relates to stripping system that utilizes a concentrated stream of air to remove a folding carton or envelope waste material from a two piece pin that is mounted to a rotating separating cylinder.
In manufacturing folding cartons, envelopes or other similar items from a sheet or web, a waste product or skeleton is typically produced. Generally, a sheet is first cut into a blank, which is the pattern of the folding carton, envelope or other desired pattern using a die or other type of cutting device. After the blank is cut, a skeleton remains surrounding the blank or within the blank if a window portion is incorporated into the folding carton. To separate the skeleton from the blank using the devices of the prior art, both the skeleton and blank are fed into a separating mechanism. The separating mechanism typically includes an upper and a lower cylinder, with the lower cylinder having a plurality of two-piece pin and sleeve assemblies that extend therefrom. Each of the pin and sleeve assemblies include a pin with a sleeve slidably coupled thereto. As the skeleton is fed between the cylinders, the pins are arranged so they penetrate and couple the skeleton to the lower cylinder while the folding carton blank continues through the manufacturing process. The skeleton is removed from the lower cylinder by sliding the sleeve over the pin to force the skeleton from the pin.
Currently, different types of mechanisms have been used to slide the sleeve over the pin to remove the waste material from the pin. For instance, the sleeves may be slid over the pin through the use of magnetic force. Specifically, a magnet is mounted within the stripping device and uses its magnetic polarity to slide the sleeve over the pin. Using a magnet to remove the waste from the pin also suffers from a number of drawbacks. In particular, the magnets are sometimes heavy and difficult to mount within the cylinders of the stripping mechanism.
Further included in the current carton and envelope manufacturing processes are assemblies which transfer the blank and skeleton from the cutting mechanism to the separating mechanism. In some instances, the assembly is a guide roller assembly by which the blank and skeleton are moved or slid along a support plate by rollers. There is a danger in utilizing such a system that the blank and skeleton will not be moved precisely together, thereby not remaining in registration with one another. If the relative positioning of the blank and the skeleton are thus altered, there is a chance that the pins of the stripping device may inadvertently pierce, and thereby destroy, the blank instead of or in addition to piercing the skeleton.
Accordingly, there remains a need for a stripping system that will efficiently remove waste material from the pins of a two piece pin and sleeve assembly. The present invention fills this need, as well as various other needs.